The document is a question paper for a network security course, detailing various questions across multiple topics including cryptographic algorithms, digital signatures, and security protocols. It is structured into several sections, each requiring different numbers of questions to be attempted, emphasizing the necessity of diagrammatic representations and explanations. Total marks for the paper are 100, with a time limit of three hours.

1. N e t w o r k S e c u r i t y
Q u e s t i o n P a p e r ( A p r i l – 2 0 1 5 ) [ R e v i s e d S y l l a b u s ]
1 | Page
M u m b a i B . S c . I T S t u d y
F a c e b o o k | T w i t t e r | I n s t a g r a m | G o o g l e + | Y o u T u b e
– Kamal T.
Time: 3 Hours Total Marks: 100
N.B.: (1) All Question are Compulsory.
(2) Make Suitable Assumptions Wherever Necessary And State The Assumptions Made.
(3) Answer To The Same Question Must Be Written Together.
(4) Number To The Right Indicates Marks.
(5) Draw Neat Labeled Diagrams Wherever Necessary.
Q.1 Attempt Any Two of The Question: (10 Marks)
(A) Write a note on SET Model. (5)
(B) Give various definition of Collision-Free Hash Function. (5)
(C) Write a note on PGP Certificate that will cover Introducer Trust and Certificate Trust.
Give Example.
(5)
(D) Sate and Explain various Fields present in an Audit Record. (5)
Q.2 Attempt Any Three of The Question: (15 Marks)
(A) State and Explain Shift Cipher Algorithm with example. (5)
(B) State and explain steps involved in Permutation Cipher. Also give an example. (5)
(C) Explain how Key is generated using a Linear Feedback Shift Register. (5)
(D) Explain Variation available in DES. (5)
(E) State and explain Chinese Remainder Theorem with example. (5)
(F) State and Explain Vigenere Cipher Algorithm with example. (5)
Q.3 Attempt Any Three of The Question: (15 Marks)
(A) Explain in detail the concept of the Digital Signature. (5)
(B) Write a note on Hash Function from Cryptosystem. (5)
(C) Explain in details Station-to-Station Protocol. (5)
(D) Explain Diffie-Hellman Key Exchange Algorithm with example. (5)
(E) Explain the concept of Timestamping. (5)
(F) Explain Transmission of Session Key using Kerberos. (5)
Q.4 Attempt Any Three of The Question: (15 Marks)
(A) Define Computer Security and three Key Objective of Computer Security. (5)
(B) What is the OSI Security Architecture? (5)
(C) List and briefly define any two categories of Security Services. (5)
(D) Draw and Explain Model for Network Security. (5)
(E) State and Explain the challenges of Computer Security. (5)
(F) List and briefly define categories of Passive Security Attacks. (5)

2. N e t w o r k S e c u r i t y
Q u e s t i o n P a p e r ( A p r i l – 2 0 1 5 ) [ R e v i s e d S y l l a b u s ]
2 | Page
M u m b a i B . S c . I T S t u d y
F a c e b o o k | T w i t t e r | I n s t a g r a m | G o o g l e + | Y o u T u b e
– Kamal T.
Q.5 Attempt Any Three of The Question: (15 Marks)
(A) Draw diagram and explain X.509 Certificate Format. (5)
(B) Explain the use of Key rings with example. (5)
(C) Write a note on S/MIME functionality and Key Management Functions. (5)
(D) What all are the advantages of Kerberos Version 5. (5)
(E) Explain any two steps of Kerberos. (5)
(F) Explain PKIX Management Functions. (5)
Q.6 Attempt Any Three of The Question: (15 Marks)
(A) List & Explain Applications & Advantages of IPSec. (5)
(B) Explain Oakley Key determine Protocol & how does it work. (5)
(C) Explain any two Phases of Handshake Protocol. (5)
(D) Explain Buffer Overflow Attack on SSL. (5)
(E) Draw and Explain ESP (Encapsulating Security Payload) Format. (5)
(F) Write a note on IKE (Internet Key Exchange) Protocol & SA (Security Association). (5)
Q.7 Attempt Any Three of The Question: (15 Marks)
(A) What is a DDoS Attack? State and Explain its Countermeasures. (5)
(B) What is the role of compression in the operation of a virus? Explain with diagram. (5)
(C) Explain the concept of Honey Pot. (5)
(D) What is an Application-Level Gateway? Explain. (5)
(E) Write a note on different Firewall Configurations. (5)
(F) Write a note on Packet Filter Firewall. (5)